A class of automobiles which have a high power-to-weight ration are often referred to as high performance cars. Some of the automobiles in this class are often referred to as street racers. It is desirable that the power from an internal combustion engine in these automobiles be maximized. Inasmuch as it is necessary that these automobiles have a muffler, the muffler must be one which attenuates the sound from the exhaust gases but creates the least back pressure, so that there is a minimization of loss of power due to the muffler. Mufflers of this general type are typically referred to as xe2x80x9chigh performance mufflers.xe2x80x9d In addition to attenuating the sound of the exhaust gases with a minimum of back pressure, the sound of exhaust gases leaving the muffler must not only have an acceptable volume, but also have a deep throaty high performance sound. The deep throaty high performance sound is a particular desirable feature for many persons associated with high performance cars. All of the desired features must be included in a small or compact muffler which is sturdy and economical to manufacture.
The present invention is directed to a high performance muffler for modifying sound waves of internal combustion engine exhaust gases. The muffler includes an inlet adapted for connection to an internal combustion engine exhaust system to receive the exhaust gases from an internal combustion engine. A muffler body is connected to the inlet for receiving the exhaust gases. The muffler body includes a shell which has a width greater than its height. The shell has a pair of spaced apart opposed panels. An outlet is connected to the muffler body to receive exhaust gases from the body which flow through the body in a defined flow path. The muffler body has a first expansion chamber adjacent to the inlet to receive exhaust gases from the inlet to allow the exhaust gases to expand. The first expansion chamber extends across the width of the muffler body. A first reduced opening is defined in the muffler body communicating with the first expansion chamber to receive exhaust gases from the first expansion chamber. The first reduced opening also extends across the width of the muffler body. A second expansion chamber in the muffler body is adjacent to the first reduced opening and receives exhaust gases from the first reduced opening. The second expansion chamber also extends across the width of the muffler body. The muffler body has a second reduced opening extending across the width of the muffler body and communicates with the second expansion chamber to receive exhaust gases from the second expansion chamber. The second reduced opening and the first reduced opening cooperate to direct the flow of exhaust gases through the muffler body in a sinuous flow path. A third expansion chamber which extends across the width of the muffler body is positioned adjacent to the second reduced opening and receives exhaust gases from the second reduced opening. The third expansion chamber communicates with the outlet to allow exhaust gases to leave the muffler body. The volume of the sound of the exhaust gases passing through the muffler body is decreased by conversion of a part of the sound energy to heat energy and the frequency of the sound of the exhaust gases is modified in the muffler body.